Dyeing



J. H. HEAP Feb. 7, 1933.

DYE ING Filed Aug. 22, 1930 6 Sheets-Sheet 1 OOvOOOOQOOOOOOOOOOQOO 00:009000 J. H. HEAP Feb. 7, 1933.

DYE ING Filed Aug. 22, 1950 6 sheets-shed 2 //v vc/v Tag Feb. 7, 1933.

Filed Aug. 22, 1930 J. H. HEAP DYE ING 6 Sheets-Sheet 3 J. H. HEAP DYEING 6 Sheets-Sheet 4 Filed Aug. 22, 1930 2 P 41 2 x X L W b o |||I \II I o 0 w J/ P V 1| W 0 ---i 0 0 1 3 K a m k w v c. m 0 X 1 00 P 7 M M m F /-v K'- JH- W J. H. HEAP Feb. 7, 1933.

DYEING Filed Aug. 22, 1930 6 Sheets-Sheet 5 Fig. 10.

J. H. HEAP DYEING Feb. 7, 1933.

Filed Aug. 22, 1930 6 Sheets-Sheet 6 Patented Feb. 7, 1933 UNITED STATES JOHN HUDSON REAP, OF ROCHELLE, ENGLAND DYEING Application filed August 22, 1930, Serial No. 477,106, and in Great Britain October 28, 1928.

This invention relates to the dyeing of textile materials or products by passage of the fabric or the like through a-bath containing dye liquor which is positively moved to ensure a more thorough and intimate contact of the dye with the fibre than is obtainable due to mere movement of the material through the bath.

The objects of the invention comprise improved processes of the above kind by means of which the dyeing can be made continuous and expedited while ensuring uniform and satisfactory results and whereby it is made possible for instance to dye with the notably fast vat dyes certain classes of fabrics containing fibres which have hitherto in practice been excluded from treatment with such dyes on account of the destructive action of the caustic liquors involved in their applica-' tion. 'Another object is the rapid, uniform and generally satisfactory dyeing of knitted goods and others in tubular condition and improved constructions of apparatus for dyeing processes are also in view.

rapid dyeing of textile products according to which the fabric, yarn or other goods to be dyed is passed in extended condition at a determined relatively high speed through a bath of dye liquor while the liquor is projected against and propelled positively through the material.

The invention further consists in a dyeing process of the kind referred to according to which dye liquor is circulated positively and uniformly through the fabric to be dyed at a speed preferably approaching the maximum permitted by the texture of or otherwise possible without damage to the fabric while the latter is moved uniformly at as rapid a rate as possible consistent with obtention of the de th of shade required in a single passage 0 the fabric through the bath.

The invention further consists in a dye- 5 ing process according to either of the preceding paragraphs wherein the material while in the liquor is held in extended condition by the action of substantial presthereof.

The invention consists in a process for the sure difference of the liquor on opposite sides a ous process ofdyeing w1th anthraqumone or 100 The invention further consists in a process accordmg to any of the three preceding paragraphs wherein the fabric or the like while in the bath is moved at a relatively lughspeed in proximity to means directing the l quor at a rapid rate through the material 1n such a way that the fabric is held extended for uniform dye penetration while forcible contactof the material with said means is avoided.

The invention further consists in a process n accordance with any of the four precedmg paragraphs applied to the dyeing of fabric in tubular condition, more especially warpless or knitted fabrics and separate more or less closed articles, and involving inflation of the tubular fabric or articles by introduction of the dye liquor into the interior at a pressure such as ensures a flow of liquor through the material of the fabric and removal of the liquor from the exterior.

The invention further consists in a process according to any of the five preceding paragraphs wherein the dye concentration of the liquoris maintained practically constant by continuous additionvto the liquor of determined quantities of dye equivalent to that extracted by the moving material.

The invention further consists in a process according to any of the six preceding paragraphs in which the dyeing liquor is circulated in such a manner that the contents of the vessel are passed'through the fabric in say for example fromvless than one to a very few minutes.

The invention further consists in a process of dyeing materials liable to injury by lengthened contact with the chemical constituents of or incapable of being evenly impregnated with the dye liquor comprising positively circulating the liquor through the thickness of the yarn or fabric while moving the same in an extended condition through a vessel containing the liquor at a speed ensuringonly a short immersion and adding continuously to the circulating liquor suflicient dye to compensate for that abstracted by dyeing the moving material.

The invention further consists in a continuvat dyes materials such as woollen or other goods liable to injury by lengthened contact with the chemical constituents of the dye l1quor comprising positively circulating the liquor at a suitable temperature through the thickness of the yarn or fabric while moving the same in an extended condition through a vessel containing the-liquor at a speed ensuring only a short immersion and addin continuous y to the circulating liquor su cient dye to compensate for that abstracted by dyeing the moving material.

The invention further consists in a method of dyeing fabric in the piece, such as knitted or other goods in tubular form comprising feeding the fabric at uniform determined speed through a vessel or conduit containing dyeing liquor at a suitable temperature while the fabric is surrounding a liquid su ply source, positively circulating the liquor om the supply source through the thickness of the fabric to maintain the same in a distended condition while moving through said vessel or conduit and "adding continuously to the circulating liquor sufficient d e to compensate for that abstracted by dyeing the moving fabric.

The invention further consists in apparatus for carrying out substantially continuous rapid dyeing processes such as those set forth in any of the preceding paragraphs comprising a dyeing vessel with submerged inlet and outlet means for the liquor, the

former means being adapted for forcible in-- troduction of the liquor as in the form of jets, liquor circulating means and means for passing the material to be dyed through the vessel between said inlet and outlet means.

The invention further consists in apparateus for carrying out substantially continuous rapid dyeing processes such as those set forth in the foregoing paragraphs comprising a dyeing vessel with perforated tube or duct means normally submerged in the liquor and connected with a source of liquor supply for projecting jets of liquor and means for drawing the material through the vessel.

' The invention further consists in apparatus for carrying out rapid continuous dyeing processes comprising a vessel containing dyeing liquor at a suitable temperature, means for continuously traversing fresh fabric to be dyed through said vessel at a determined d, means for passing the dyein liquor by clrculation through the material 0 said fabric during said traversing and means for addto the circulating liquor determined quantitles of dye to maintain the dyeing strength of the liquor suificiently constant.

The invention further consists in apparatus according to any of the three preceding paragraphs having means for moving flat piece goods continuously at full width through a wide, close-walled, conduit-like vessel filled with dyeing liquor which passes for example by circulation through perforations in the walls across the conduit through the material of the fabric.

The invention further consists in apparatus for dyeing goods in tubular condition according to an of the three paragraphs next but one prece ing having a liquor supply pipe with a perforated portion submerged in the liquor in the vessel and in which the tubular fabric loaded on an unsubmerged portion of the supply pipe is fed therefrom downwardly into and through the liquor in the vessel and out from the latter with the liquor from the perforated pipe distending and passing through the fabric and being returned by suitable connections to the circulating means.

The invention further consists in apparatus according to the preceding paragraph having a cylindrical conduit-like vessel formed as a return bend or U tube with the upper portion of one limb gradually trans forming from a cylindrical to a flattened cross section of approximately corresponding perimeter and having a central perforated supply pipe extending from a liquor circulating means, down the cylindrical limb, round the bend, and up into the transforming region in which apparatus the tubular fabric is fed down the cylindrical and up the flattened limbs.

The invention further consists in apparatus according to the paragraph next but one preceding having a conduit-like vessel formed as a return bend or U tube with one limb of cylindrical section and the other limb of a flattened cross section of approximately corresponding perimeter and having a central perforated supply pipe extending from a liquor circulating means, down the cylindrical limb, round the bend to approach the lower part of the other limb, in which apparatus the tubular fabric is fed down the cylindrical and up the flattened limbs.

The invention further consists in apparatus according to any of the three preceding paragraphs wherein lengths of the tubular fabric loaded alternately on to change-over connections between the supply pipe and the liquor circulating means are appropriately joined with one another to render continuous the passage of fabric through the dyeing vessel.

The invention further consists in apparatus according to any of the three paragraphs next but five preceding having a rotary carrying and liquor controlling member which may be partially submerged in a vat or other dyeing liquor containing vessel and is fitted round its circumference with means providing for the quick attachment and detachment of sets of radially or other wise directed nozzles for the reception and holding of more'or less enclosed separate articles such for example as stockings and said member while continuously rotating and besultable ports the flow of liquor from IOr pelling means to the interior of those articles which are being drawn through the vessel of liquor and deflects it from the articles after they are withdrawn from the vessel so that they can be exchanged.

The invention also consists in improvementsin or relating to dyeing processes and apparatus for carrying the same into effect as indicated in the following description and hereinafter claimed. i

Referring now to the accompanying drawin s:

- igure 1 is a side elevation partly in section of one form of apparatus for dyeing woven fabric according to this invention;

Figure 2 is a plan of the apparatus shown in Figure 1;

Figure 3 is a side elevation part1 in section of a form of ap aratus ada te for use with tubular goods, for instance nitted fabrics; a

Figure 4 is a plan of the apparatus shown in Figure 3;

Figure 5 is an elevation of a modified form of apparatus for handling woven goods;

- Figure 6 is a plan corresponding to Figure 5' Figures 7 and 8 are respectively an elevation and aplan of a modified form of apparatus for handling goods in tubular condition' Figures 9 and 10 are respectively a part sectional elevation and a plan of a modified dyeing vessel operated on the same lines as the apparatus shown in Figures 7 and 8;

Figures 11 12 and 13 are respectively a transverse part sectional elevation, a longitudinal sectional elevation and a plan 0 a form of rotary apparatus suitable for dyeing separate and more or less closed articles such as stockings;

Figures 14, 15 and 16 are detail fragmental sections to an enlarged scale of certain parts of the apparatus shown in Figures 11 to 13.

In carrying the invention into effect in the convenient form of apparatus shown in Figures 1 and 2 of the drawings for the treatment of fiat piece goods, the main vessel a which contains the dye liquor is provided with a system of connectionsb, b, &c., to a pipe 0 running to the suction side of a circulating pump d, the discharge of the latter being led back over the vessel a through a pipe 6 to a system of submerged spray pipes. These latter comprise two superposed transversely arranged sets of parallel pipes f, f bridging respectively two superposed pairs of parallel pipes g, g which are fed from the pipe 6 by branch connections h.

The liquid in use is maintained at a suitable temperature by a number of steam heated pipes or a coil heater located in the bottom of the vessel (1.

into the vessel a through the dye liquor and out via a system of leading-in, guide and drawing-out rollers j, j, 7' respectively, the intermediate ones being disposed so as to guide the fabric in between the two superposed sets of tubes f and these latter are slotted or erforated so that the liquor withdrawn rom the bath by the pump d and re.-

1 turned via said tubes f is directed from the latter forcibly in a number of jets against the fabric from above and below same. The fabric is drawn through the bath at a relatively rapid rate by means of rollers j which are driven by an electric motor or any other source of drive allowing of speed variation.

Throughout the dyeing operation the strength of the liquor is constantly maintained by adding fresh dye solution from a tank l connected by a pipe Z to the vessel (1, a suitable regulating valve Z being interposed. The pi e Z and it is to be noted also all the connections I), b, &c., are disposed to the one and same side of the moving fabric. The connections being distributed in this way constant circulation of the whole of the dye liquor from every part of the bath is ensured and also introduction of the fresh dye as above enables it to be thoroughly mixed in the liquor before same passes back via the pump to the spray pipe f.

The rate of addition of fresh liquor from the tank Z will, of course, depend primarily upon the amount of dye extracted by the fabric and also upon a number of other factors including rate of travel of the fabric through the bath, the length of fabric submerged at any given time and the rate of circulation of the liquor through the fabric which is controllable by regulation of the speed of running of the pump d.

According to another embodiment of the invention which is applicable to the dyeing of tubular goods, e. g. tubular knitted goods, an example of apparatus which may be used is shown in Figures 3 and 4 and diflers essentially from that previously described by substitution for the spray pipe arrangements thereof of a discharge pipe 1) which is submer ed for a considerable part of its length in the liquor and runs longitudinally in the centre of the vessel a.

The submerged part p .of the pipe p is perforated and terminates inan upwardly turned bowed pipe 12 which may also have perforations, the purpose of the part being later explained.

In the connection between the pipe p and the discharge from the pump is provided a three-way valve 9 having easily made connecting means at the branches 9, g and connectable to each thereof are two parallel pipes g, g leading via suitable valves g q from In operation the fabric to be dyed is passed the discharge of pump (1. The parallel pipes g and g are arranged for swingingbeyond their respective valves 9 9 so that either of the parallel pipes may be connected to the valve 9 and so with the pipe p. In operation lengths of tubular goods knitted or otherwise are loaded upon the parallel pipes 9 g and after coupling the perforated pipe p to one of these pipes the fabric is carried oyer the valve 9 and passed down into the liquor, being drawn along the submerged perforated part p and finally leaving the vessel by the drawing out rollers 3' in flattened cond tion, the bowed pipe 12 assisting the material in its transformation from circular condition to flat. In this case, perforations may preferably be formed regularly in the discharge pipe over the whole of its submerged circumference so that the material is distended radially outwards by pressure of the liquor jets. Further, it will be appreciated that since the tubular material envelopes the perforated discharge pipe, the liquor will be obliged to pass completely through the material.

In practice when starting up, an end cloth may usually be attached to the leading end of the material and be first drawn over the submerged portion 39 of the pipe and over the draw rollers j. The use of an end cloth ensures that the period of submersion is constant for all parts of a length of fabric. The fabric thereafter is traversed continuously through the dyeing vessel under guidance of the pipe which it envelops and during its traverse is kept distended by the circulation of the dye liquor from the perforated pipe p through the material of the fabric and back to the pump, the tubular. fabric coming out of the dyeing vessel in a flat condition and completely dyed by its single rapid passage through the vessel and thence it may be rolled or passed in roped condition for any other desired treatment prior to it being dried to a required width or otherwise treated. I The fresh pieces of fabric are fed on to the uncoupled length of parallel supply pipe while another piece is being taken oif the coupled one and as the end of one piece is approached a suitable portion is pushed bodily from the parallel pipe past the connecting means on to the perforated pipe and coupling and uncoupling of the pipes is effected and the fresh length joined to the end of the length which is approaching its termination. In this way the fabric is fed continuously through the dyeing vessel while the dyeing strength of the liquor is kept up during its constant circulation through the fabric by addition of dye from the tank Z.

In a simplified construction the perforated pipe 77 instead of being supplied by means of the twin pipe and three-way valve arrangement qg*'of Figures 3 and 4 may be connected to a simple discharge p pe by means of a suitable trunnion so that the part of the pipe p normally submerged in the liquor can be rotated or swung up out of the liquor when the tubular material may be threaded on to it and moved on to a portion of the pipe not normally submerged. Thereafter the dyeing operation may be conducted as has been described above except that from time to time the operation has to be interrupted while the pipe is lifted up and recharged with fresh material. 1

In another modification the dyeing of flat piece goods may be carried into effect in apparatus such as is shown in Figures 5 and 6. This apparatus comprises a conduit consisting of two vertical lengths a, a connected by a chamber a at the bottom and positioned within a dyeing vessel at having means such as steam pipes at is for maintaining the liquor at a suitable temperature. The conduit is of wide, close-walled, cross section with its edges formed by the walls of the main vessel and the wide sides of the conduit are perforated throughout upon both sides. The conduit, therefore, divides the vessel into a central compartment a and two outside compartments a a which are in connection with one another externally andbelow the chamber joining the-bottoms of the two halves of the conduit while l quor can fill the conduit and be circulated across it through the perforations in its Walls.

Inlets Z), Z), &c., from the discharge pipe system c of the centrifugal pump at or other liquor circulating device are located upon the length of the central compartment a" of the dyeing vessel and from the bottom of the outer compartment at b and also from the' several points 6, 6 throughout the length on both sides connections are made to the pipe 0 running to the suction of the pump and by this means the dyeing liquor is pumped into the central compartment a and circulates across the two parts a, a of the conduit through the perforations into the outer compartments a 0; and back to the pump.

As before means in the form of a tank Z and pipe Z are provided for continuously adding determined quantities of dye to the liquor in the return line to the pump, these quantities being equivalent to the amount of dye abstracted by the fabric which is being treated.

In the chamber at the bottom a of the conduit there is provided a guide roller m the sides of which are located beneath the centres of the two parts a, a of the conduit and above the vessel roller means and 7' are provided for feeding in and taking off the fabric which is being dyed.

The fabric to be dyed, preceded by a suitable end cloth, is passed at a comparatively rapid rate of speed from the upper guide rollers 7', down through one part a of the conduit, round the guide roller m at the bottom, up through the other part a of the conduit and over the other upper ide rollers j. and during its sin le passage rough the conduit the complete yeing operation is performed,

Beamed warps of yarn may also be (1 ed in 3 apparatus as last described as also 1n the forin of apparatus shown in Figures 1 and 2. 1 In another apparatus shown in Figures 7 and 8 and'operating on tubular goods generally on the same lines, as that of Figures 3 and 4 a conduit is arranged upright andformed as a return bend or U tube, one limb a and the bottom connecting bend a being of cylindrical cross section and the section merging gradually from a cylinder to a wide, flattened conduit a of substantially similar perimeter to the cylinder at the upper end of the other limb.

Down the cylindrical limb, round the bend and some way into the transforming region there is carried a central perforated pipe, the part p thereof in the conduit a being of round section while the part p risin up into the conduit (1 is flattened and wi ened or may comprise a bowed pipe following the widening section of the conduit a.

The pump and connecting pipe systems to the perforated pipe 32 are similar in construction and operation to those described with reference to Figures 3 and 4 and the tubular fabric surrounding the pipe 12 in this instance is carried from one or other of the pipes 9 g downwards through the cylindrical limb a of the conduit round thebend at the bottom and up out of the flattened limb a, being .pulled through by the suitably driven rollers In the present apparatus the pipe 0 is connected both to the chamber a at the bottom of the apparatus where a heater k is also accommodated and by means of an embracing pipe or header 0 to several connecting points I; at various locations in both limbs of the conduit. Also dye liquor from the tank Z is led via the pipe Z to the chamber a for making up the strength of liquor.

In the modified apparatus of Figures 9 and 10 the arrangement differs from that last described in that the limb a of the U- shaped conduit is of flattened rectangular section throughout its height, the perforated pipe 12 changing its section at the bottom of the limb a and the transforming portion turning upward but terminating short of the bottom of the limb a In this case the transformation of the tubular fabric from circular to flat takes place more abruptly and rollers m, m are provided for guiding the fabric round the bend into the limb a Apart from these differences and minor differences in constructional detail the apparatus corresponds to that of Figures 7 and sand is operated in the same manner. Y I

In another form of construction'such as may substitute that of Figures 9 and 10, a vertical bath may have a vertical partition unequally dividing it from the greater part of its height from the top into two compartments, the material passing downwards into the larger compartment in which the erforated dicharge pipe is located, beneat said partition via suitable rollers or other guides and upwards out of the smaller compartment.

Another type of apparatus is shown in Figures 11 to 16 in which a rotary member or drum n is positioned above a dyeing vat 0 having a suitable form of heater is, the rotary device, which has its axis horizontal, dipping into or being partially say half immersed in the dyeing liquor.

The rotary device as shown clearly in Figu're,14 is provided around its circumference. with a number of dove-tail section projecting portions 0, 0, &c., with spaced perforations or ports 0' for holding slide members 7, r, &c., say formed from sheet metal pressings providing sets of nozzles s, s, &c., arranged complementary to the ports 0', each of the nozzles being adapted to have a stocking or other separate and more or less enclosed article fastened by its open end thereon. The drum is rotatable by suitable gearing at '2) about a hollow trunnion t blanked off at 2 toward one end into which trunnion the dye liquor is pumped through the discharge pipe e by the pump d and from which it passes into the inside of the drum n by suitable openings as t. Suitably attached as by arms to the trunnion t is a blanking off or baflle piece tfwhich conforms closely to the internal periphery of the drum and isolates the l1quor 1n the drum from certain of the ports 0 and nozzles s c'onfiningthe discharge of dye liquor to only such of the nozzles s as are submerged or practically submerged in the vat proper.

In operating this form of apparatus the sets of nozzles on the slides are all loaded with the stockings or other articles and the a the replacement of sets of nozzles while the rotary device is in movement.

With the drum set in rotation by suitable drive applied to the gearing 'v the dye liquor circulated by the pump d or the equivalent passes in at the trunnion t coaxial with the axis of rotation of the drum and is opened to each of the sets of nozzles 8 while these are performing the lower portion of the revolution, being shut off from them while they are performing the upper part.

The stockings or other articles are drawn through the dyeing vessel by the movement of the rotor and while in the liquor they are inflated by the circulating liquor which is forced through the material of the articles and effects the complete and uni-form dyeing operation during the very short period that each article is passing through the bath, the circulating liquor supply being shut off from the articles as they are being withdrawn from the vessel so that the dyed articles are removed in sets with the slides of nozzles to which they are attached and fresh loaded sets put on in their places ready for the dyeing operation. In this form of apparatus also return connections to the circulating pump are taken from various distributed points I), b, &c., of the vessel at, these branching off from the main suction pipe 0. Also, a

' tank I connected to the vessel a by the pipe Z is provided for making up the strength of the dye liquor.

Further, in such operations owing to the ver short time of contact between the fabric and the caustic constituent of the liquor, which ma in some cases be more or less in the neigh ourhood of a minute, fabrics of wool, pure or artificial silk including acetate silk and others which would be completely spoiled by ordinary dyeing operations may be successfully treated in accordance with this invention while the circulation of the dye actually through the material of the fabric produces exceedingly even colour results and also enables tubular goods to be successfully dealt with. Knitted or tubular goods operated upon according to this invention present no difliculty in respect of the known tendency of warpless fabrics to curl up at the edges and become distorted especially when placed under tension which has in other methods resulted in binding aggravated by the action of the caustic content of the bath in the case of vat dyeing when the material is not kept under the liquor throughout the dyeing process and has interfered seriously with the obtention of even results.

In addition to the foregoing all kinds of piece goods may be treated continuously by a single immersion with an enormous saving on the time occupied in treatment and separate articles such as stockings or other more or less closed articles can also be treated in bulk and with great rapidity.

Mixed yarn fabrics such as wool and natural or artificial silks or cotton and wool fabrics may also be successfully treated in accordance with the invention.

An important advantage which becomes apparent in working in accordance with the present invention is that the rates of absorption of different dyes become substantially equalized, this appearing to be due to the relatively rapid rate of movement of the liquor in relation to the fabric and the vigor with which the dye content of the liquor is brought into contact with the fibres. This advantage is of special significance when dealing with liquors containing more than one dye and considerably facilitates matching.

As a specific example of the method of dyeing according to this invention the case may be taken in which a definite jade green colour is to be produced by vat dyeing on cotton or artificial silk. The apparatus used isthat described above with reference to Figures 9 and 10 of the drawings, the material operated upon being knitted material and being dyed in tubular condition.

Into the vessel a is introduced water, the volume in use being approximately 650 gallons and about 60 pints of caustic at 66 TW. and 3 pounds of hydrosulphite are added. To the bath producedasabove there is then added 20 pounds of colour paste, namely Caledon jade green (dimethoxy-dibenzanthrone), which has previously been vatted with 4 pints of caustic and 20 pounds'of hydrosulphite. The dye liquor thus produced is circulated by the pump 03 at the rate of 650 gallons per minute while the temperature of the liquor is maintained at 112 F.

The tubular knitted fabric having been charged circumferentially on to the pipe system g, q, 9 &c., as described above it is then passed down over the perforated pipe p through the bath and out at the rate of 1% pounds per minute which may be approximately 4 yards of the material per minute.

Throughout the operation, that is, so long as the fabric is being passed through the bath in the above way, fresh dye, previously vatted, is added from the tank Z at the rate of 12 per cent. in relation to the weight of the fabric. In other words during each hour of running there is added 9.4 pounds of colour or 2.5 ozs. per minute. The paste is previously vatted with 2 pounds of caustic at 60 Tw. and 1 pound of hydrosulphite for every 10 pounds of the Caledon jade green paste referred to above, the product being diluted with a suitable amount of water to make measurement convenient. Thus, there may be 80 pints of liquor for every 10 pounds of colour and in such a case each pint carries 2 ozs. of colour and 1 pints of the soluios tion are introduced into the main body of liquor each minute.

By operating under the foregoing conditions the strength of the dye bath is maintained constant and to achieve this important condition in other modes of working by the methodsof this present invention it is only necessary to arrange for the addition of fresh dye at the same rate as that at which it is being removed from the'bath by the fabric passing therethrough. In general, of course, the dye manufacturers instructions as to vatting orotherwise making up a suitable dye solution and as to the temperatures at which dyeing should be conducted need not materially be departed from.

\Vhile the process is essentially one aiming at effective and uniform dyeing at a rapid rate and by a single passage of the fabric through the bath, the rate of travel of the fabric, given a definite working concentration of bath, must obviously depend upon the shade or depth of colour required and other factors such for instance as the submerged length of fabric and the rate of circulation of the liquor which latter may most advantageously be made as high as is permitted by the texture of the fabric or as may otherwise be possible without damage to the fabric. lVith some materials and some forms of theapparatus the rate of circulation of liquor through the fabric may amount to about 6 gallons per square foot of fabric every minute.

It is to be understood that the apparatus hereinbefore described and the methods of operating the same are given by way of example only and that modifications and additions may be introduced Without in any way departing from the nature of this invention as set forth in the foregoing statements and also that flat lengths of fabric may have their selvedge edges joined to bring them into tubular form for the purpose of operating in the same manner as for ordinary tubular goods.

I claim:

1. A method of dyeing fabric in the piece such as knitted or other goods in tubular form comprising feeding the fabric at uniform determined speed through a vesselor conduit containing dyeing liquor at a suitthereof with definite flow of liquor therethrough. v

4. A method of dyeing consisting of mtroducing into a'body of dye liquor a generally closed article to be dyed and moving it uniformly therethrough under free suspension therein, supplying liquor under pressure to the interior of said article and withdrawing liquor from the exterior thereof while the same is submerged to produce definite circulation of liquor through the material of such article and distension thereof.

5. In the method set forth in-claim 1, returning liquor withdrawn from the dyeing vessel to said liquor supply source inside the moving fabric via one of two alternative circuits, opening the other alternative circuit and charging therearound a fresh length of the tubular fabric while the original length of fabric is being fed through the vessel and before said original length has completely entered the vessel, closing said other alternative circuit and diverting the liquor therethrough from the first alternative circuit, opening the latter and connecting the fresh length of fabric to the original length, similarly feeding fresh length in turn into the vessel for dyeing treatment by manipulating said alternative circuits and recharging them with further lengths of the fabric as often as desired.

In testimony whereof I have signed my name to this specification.

JOHN HUDSON HEAP.

able temperature while the fabric is sur rounding a liquid supply source, positively circulating the liquor from the supply source through the thickness of the fabric to maintain the same in a distended condition while moving through said vessel or conduit and adding continuously to the circulating liquor suflicient dye to compensate for that abstracted by dyeing the moving fabric.

2. A method of dyeing fabric in the piece such as knitted or other goods in tubular form comprising feeding the fabric at a uniform determined speed through a vessel or conduit containing dyeing liquor at a suitable temperature while the fabric is within the range of a liquid supply source, positively circulating the liquor from said source through the thickness of the fabric to maintain the same in opened-out condition while moving through said vessel or conduit.

3. A method of dyeing piece goods in tubular form which consists in passing such goods lengthwise through the body of dyeing v liquor and subjecting the portion submerged internally to increased liquor pressure produc ng inflation and we suspension 

